2013 MTM Audi R8 RS - GT3 Auf Der Straße

MTM converts a 600hp Audi R8 LMS GT3 racecar to road duties

In the early days of motoring, there was little or no difference between road and racecars. You donned your leather jacket and goggles, drove your open-top Bentley or Bugatti to the track, competed against your opponents and drove home again.

The Jaguar C- and D-Types that won Le Mans in the 1950s, for example, were driven from Coventry to the track, raced and driven home. Other than the dedicated F1 and F2 racecars that arrived on trailers, this was how sportscar racing remained until the late 1960s. It epitomized the "run what ya brung" spirit of motorsport that only survives today at the amateur level.

And while supercar manufacturers would like to think their machinery is as adept on the racetrack as it is on Main Street, any car designed to pamper to wealthy owners is, by definition, compromised. Meeting road safety and emission laws, providing creature comforts like electric seats, A/C and infotainment will keep today's drivers happy but add weight and complexity.

Out of the box, the typical modern sports car is carrying approximately 600 lb more than a similar racecar, and the ride height is set to clear obstacles that would limit the use of ground effect aerodynamics on the track. As a result, no road-going supercar can match a real racecar, even if it has more power.

With this in mind, instead of going down the normal route of trying to make an Audi R8 work better at track days, Roland Mayer, owner of Motoren Technik Mayer GmbH (MTM) in Wettstetten, Germany, decided to turn the argument on its head and make an actual racecar street legal. "Audi offers the R8 Clubsport for track days, which is based on the R8 GT road car. But we decided to approach it from the other direction and get street homologation for the R8 LMS racecar. Fortunately, we can do that because we're a certified car manufacturer in Germany," he explained.

"We based the car on an FIA GT3-spec R8 LMS that we campaigned in the International Sprint GT Series, which is one of the DTM support races," Roland said. "The motor is showroom stock, and limited to 550hp by an air restrictor. It normally runs on 18" BBS centrerlock wheels but, for the street, we use 18" front and 19" rear with Michelin Pilot Sport Cup tires, which works perfectly."

Entered into the 2013 Tuner Grand Prix (an annual German event), the MTM R8 RS won convincingly against some much more powerful adversaries such as 700hp supercharged Corvettes. Admittedly, MTM had installed its TuV-approved ECU upgrade, which takes the motor to 602hp.

We've driven the R8 V10 with this MTM conversion and can attest to its performance gains, but it has a greater influence on performance when you consider the R8 LMS weighs about 2800 lb, which compares favorably to the 550hp R8 V10 Plus, which tips the scales at 3450 lb.

The superior power-to-weight ratio obviously improves acceleration but it also has a positive effect on braking, handling and mechanical grip.

Like a fox in the chicken coop, MTM seemed to have an unfair advantage since it not only had a racecar entered in a tuner event, but it was piloted by professional race driver and former MTM mechanic Florian Gruber. He drives the R8 in the Sprint GT Series, so had no problems in the Tuner GP. He's been successful in various championships, using his skills as a pro driver and ace mechanic to help him when setting-up his cars.

On The Road

Clambering into the R8 RS driver's seat required a fair measure of agility. You have to tackle the side intrusion bars of the rollcage and then wiggle down into the snug-fitting Recaro race seat with its extended head protection.

The car's weight is instantly felt under full acceleration, although the lack of soundproofing in the cabin definitely adds to the visceral experience when driving the car at any speed.

The engine might be stock, but the paddle shift-operated Hor Technologie sequential transmission most certainly isn't. Like most competition cog-swappers, you use the clutch to select first and neutral, but shift up and down with the pedal flat on the floor. The single-mass flywheel and straight-cut gears whine like banshees all the while.

Full noise in second from low revs produces a throaty roar that quickly morphs into the distinctive V10 tone, and finally a scream like ripping silk behind your head. The stark cabin further amplifies the mechanical symphony, with the decibel level directly related to throttle position.

The Bosch DDU8 LCD instrument display relays information on speed, RPM, gear, fuel, oil and water temp and can also be used for lap times. There are also traction control and ABS settings, both of which are driver adjustable but the data on the small screen is too much to absorb on a hot lap, so most drivers only glance at the instruments on the main straight when they have a few seconds to breathe and take stock.

This is also why racecars use shift lights that flicker green, orange and then red to inform them of the approaching redline, allowing you to time your upshifts before the 8500rpm limiter as you focus down the track.

One of the requirements for TuV approval on the car was a reasonable ride height for the road, and so the MTM R8 RS sits about 35mm higher than the GT3 version. The fully adjustable race suspension can be raised and softened, so the ride is no worse than many tuner cars we've driven.

That said, in a machine that looks like this, a firm ride and near-apocalyptic soundtrack clearly come with the territory. And since it's not everyday you see a racecar in full livery driving down the road, the looks of astonishment we collected while driving the Audi R8 RS on the public highway were simply priceless.

In addition to the graphics, the exterior was festooned with aero aids such as the front splitter, flics and the huge rear wing. But these aren't there for show, although you do need to be travelling at high speed to experience their full aerodynamic advantage. In fact, there's a long sweeping curve near MTM's HQ and while I might hesitate to take it flat-out in a regular car, we could feel the R8 RS actually hugging the tarmac as speed increased, foot flat on the board in fourth gear.

While the cornering ability would be even better with its ride set at the track height, it was already better than any supercar of its size and weight. And the sticky Michelin tires contributed to the overall impression. Admittedly, they don't have the grip of slicks, but straddle the line between road-legal and track tires. Importantly, they will also work well relatively on a wet surface provided there's not much standing water.

In the tighter bends, the car turned like a go-kart, its lower mass, smaller steering wheel and rose-jointed suspension removing any last vestige of road car vagueness. The typical racecar seating position put you nearly on the floor, giving you a direct connection to the road.

As you can imagine, the driving experience is memorable. The problem is, it felt like a racecar on the road, but how many times have you heard that cliche? However, on this occasion, it's the only way to accurately describe the MTM R8 RS.